An increasing number of textile machines are provided with Jacquard devices for the production of fabrics with designs or ornamental motifs produced during the weaving or knitting phase by the selection of appropriate moving parts, according to the general principle of modifying the position and/or the path of the part in question (needle, jack or under-needle, sinker, heald, and similar). Essentially, a conscious discrimination is made between opposite positions and/or commands such as "inside-outside", "up-down", "north-south", and similar. In stocking and circular or flat knitting machines, with rotating cylinders and stationary cams or vice versa, the selection jack is usually provided with one or more butts against which an external device, actuator and/or selector acts. Normally, there is an impact between the latter and the stub of the incoming jack (in other words between moving and fixed parts or between moving parts only), the force of which varies with the operating speed and produces violent lateral impacts, vibrations, acceleration, heat, friction and wear in excess, which sometimes cause mechanical breakages. However, in addition to the said lateral impact, the normal selection is characterized by other limits which are even more evident in fast machines. One of these is represented by the necessity of widening the selection window or region, since, owing to the speed, the impact of the butts of the jacks on the raising cam must take place with a slight inclination, which may be less than 20 degrees. Another limit is set by the width of the selector (and the corresponding lateral inclined plane) which may be as much as 10 mm or more, this being necessary to allow the jack to complete its path, in other words to abruptly re-enter the cylinder or needle bed, passing behind the raising cam, without damage, in time. Another limit is represented by the fact that, after the impact with the external selector provided with the usual inclined plane, the jack violently re-enters towards the cylinder and is practically free, and therefore subject to strong recoils and vibrations. Another limit is represented by the fact that, independently of the operating speed, the normal width of the said selector complete with inclined plane does not permit the disposition of the jack butts very close together, for example, the use of a single selector of the actuator to select all the jacks, 13-13a, FIG. 21, in a similar way to the single-magnet device. A further limit is represented by the fact that electronic machines remain definitively characterized and conditioned by the original selection method, whether single-magnet device or actuators. Since each of these systems offers its own advantages, known to experts (rapid change of gauge, costs and wear of the materials, needle selection with two or three technical ways, and others), that a modern knitting factory must be flexible and rapidly adaptable to the changing market requirements with Jacquard and other types of production, it appears advantageous to have available a versatile machine capable of using, according to circumstances, various and/or different selection systems, or of producing different knitted structures at high speed.